TypescriptAPIUtils: add findLastNodeOfType function

Author: davidkudera

packages/typescript-api-utils/sourceFiles/findLastNodeOfType.ts

@@ -0,0 +1,22 @@
+import * as ts from 'typescript';
+
+
+export function findLastNodeOfType<T extends ts.Node>(kind: ts.SyntaxKind, sourceFile: ts.SourceFile): T|undefined
+{
+	let lastNode: T = undefined;
+
+	function findLoop(parent: ts.Node): void
+	{
+		ts.forEachChild(parent, (child: ts.Node) => {
+			if (child.kind === kind) {
+				lastNode = <T>child;
+			}
+
+			findLoop(child);
+		});
+	}
+
+	findLoop(sourceFile);
+
+	return lastNode;
+}

packages/typescript-api-utils/sourceFiles/index.ts

@@ -1,2 +1,3 @@
 export * from './findNode';
+export * from './findLastNodeOfType';
 export * from './lookupSourceFile';

packages/typescript-api-utils/tests/tests/sourceFiles/findLastNodeOfType.ts

@@ -0,0 +1,31 @@
+import {findLastNodeOfType} from '../../../';
+import {expect} from 'chai';
+import * as ts from 'typescript';
+
+
+describe('#sourceFiles/findLastNodeOfType', () => {
+
+	describe('findLastNodeOfType()', () => {
+
+		it('should return undefined if node does not exists', () => {
+			const sourceFile = <ts.SourceFile>ts.createSourceFile('/main.ts', '', ts.ScriptTarget.Latest);
+
+			expect(findLastNodeOfType<ts.ClassDeclaration>(ts.SyntaxKind.ClassDeclaration, sourceFile)).to.be.equal(undefined);
+		});
+
+		it('should return node', () => {
+			const sourceFile = <ts.SourceFile>ts.createSourceFile(
+				'/main.ts',
+				'function() {const a = 1; const b = 2;}',
+				ts.ScriptTarget.Latest
+			);
+
+			const node = findLastNodeOfType<ts.Identifier>(ts.SyntaxKind.Identifier, sourceFile);
+
+			expect(node.kind).to.be.equal(ts.SyntaxKind.Identifier);
+			expect(node.text).to.be.equal('b');
+		});
+
+	});
+
+});